TCEQ Interoffice Memorandum

To: Jaime Garza, Regional Director

From: Sabine Lange, Ph.D. Toxicology Division, Office of the Executive Director

Date: August 4, 2015

Subject: Toxicological Review of 2014 Ambient Air Network Monitoring Data in Region 15, Harlingen

Conclusions  All 24-hour average and annual average concentrations of 84 volatile organic compounds (VOCs), 16 polycyclic aromatic hydrocarbons (PAHs), and two metals measured in total suspended particulate matter (TSP) were below their respective Texas Commission on Environmental Quality (TCEQ) air monitoring comparison values (AMCVs) and would not be expected to cause adverse health effects or vegetation effects.

Background Ambient air sampling conducted at two monitoring network sites in Region 15, Harlingen during 2014 was evaluated by the Toxicology Division (TD). Table 1 indicates the location and monitored compounds at two Community Air Toxics Monitoring Network sites in Region 15. Hyperlinks are provided in Table 1 for more detailed information on each monitoring site. The TD reviewed air monitoring summary results for VOCs, PAHs, and speciated metals data from 24-hour TSP samples collected every sixth-day. For a complete list of all examined chemicals, please see Lists 1, 2, and 3 in Attachment A.

The TCEQ Monitoring Division reported the data for all chemicals evaluated in this memorandum. All data collected [84 VOCs, 16 PAHs, and 2 metals (TSP)] from the Brownsville and Mission monitoring sites met the data completeness objective of 75 percent data return. Twenty-four-hour air samples collected every sixth-day for a year are designed to provide representative long-term average concentrations. In order to be able to evaluate 24-hour monitoring data more fully, TCEQ has developed 24-hour AMCVs for specific chemicals. As such, 24-hour samples were compared to the available TCEQ 24-hour AMCVs for 1,3-butadiene and benzene. However, because short-term or peak concentrations are not necessarily captured by 24-hour samples, daily concentrations have limited use in evaluating the potential for acute health effects. Therefore, the TD evaluated the reported annual average concentrations from 24- hour samples for each target analyte for potential chronic health and vegetation concerns by comparing measured chemical concentrations to long-term AMCVs or, for lead, to the applicable comparison level. More information about AMCVs is available online at: http://www.tceq.state.tx.us/implementation/tox/AirToxics.html#amcv. Garza et al August 4, 2015 Page 2 of 4

Table 1. Monitoring Sites Located in TCEQ Region 15

City and Site Location County EPA Site ID Monitored Compounds

Brownsville, 344 Porter Cameron 48-061-0006 VOCs, PAHs, and Metals Drive (TSP) Mission, 2300 North Hidalgo 48-215-0043 VOCs and PAHs Glasscock

Evaluation VOCs Of the 84 target VOCs at the Brownsville and Mission sites, all were either not detected or were below their respective long-term AMCVs; additionally, 1,3-butadiene and benzene were below their 24 hour AMCVs. Therefore, exposure to the measured concentrations would not be expected to cause chronic adverse health or vegetation effects.

Metals (TSP) Arsenic was not detected in any 24-hour TSP metals samples collected at the Brownsville monitor during 2014. Lead was only detected once out of 53, 24-hour TSP metals samples and detected levels were below levels of health concern.

PAHs Of the 16 reported PAHs at the Brownsville and Mission monitoring sites in 2014, all were either not detected or were below their respective long-term AMCVs and exposure to the measured concentrations would not be expected to cause chronic adverse health effects.

If you have any questions regarding the contents of this review, please do not hesitate to contact Sabine Lange via email at [email protected] or by phone at (512) 239-3108.

Garza et al August 4, 2015 Page 3 of 4

Attachment A

List 1. Target VOC Analytes in Canister Samples

1,1,2,2-Tetrachloroethane Acetylene Trichloroethylene 1,1,2-Trichloroethane Benzene Trichlorofluoromethane 1,1-Dichloroethane Bromomethane Vinyl Chloride 1,1-Dichloroethylene Carbon Tetrachloride cis-1,3-Dichloropropene 1,2,3-Trimethylbenzene Chlorobenzene cis-2-Butene 1,2,4-Trimethylbenzene Chloroform cis-2-Hexene 1,2-Dichloropropane Chloromethane cis-2-Pentene 1,3,5-Trimethylbenzene Cyclohexane m-Diethylbenzene 1,3-Butadiene Cyclopentane m-Ethyltoluene 1-Butene Cyclopentene m/p Xylene 1-Hexene & 2-Methyl-1- Dichlorodifluoromethane n-Butane Pentene Dichloromethane n-Decane 1-Pentene Ethane n-Heptane 2,2,4-Trimethylpentane Ethylbenzene n-Hexane 2,2-Dimethylbutane Ethylene n-Nonane 2,3,4-Trimethylpentane Ethylene Dibromide n-Octane 2,3-Dimethylbutane Ethylene Dichloride n-Pentane 2,3-Dimethylpentane Isobutane n-Propylbenzene 2,4-Dimethylpentane Isopentane n-Undecane 2-Chloropentane Isoprene o-Ethyltoluene 2-Methyl-2-Butene Isopropylbenzene o-Xylene 2-Methylheptane Methyl Chloroform p-Diethylbenzene 2-Methylhexane Methylcyclohexane p-Ethyltoluene 2-Methylpentane Methylcyclopentane trans-1,3-Dichloropropene 3-Methyl-1-Butene Propane trans-2-Butene 3-Methylheptane Propylene trans-2-Hexene 3-Methylhexane Styrene trans-2-Pentene 3-Methylpentane Tetrachloroethylene 4-Methyl-1-Pentene Toluene

List 2. Target Metal Analytes

Arsenic (TSP) Lead (TSP)

List 3. Target PAH Analytes

Acenaphthene Benzo (a) anthracene Benzo (ghi) perylene Acenaphthylene Benzo (a) pyrene Benzo (k) fluoranthene Anthracene Benzo (b) fluoranthene Chrysene Garza et al August 4, 2015 Page 4 of 4

Dibenzo (a,h) anthracene Indeno (1,2,3-cd) pyrene Pyrene Fluoranthene Naphthalene Fluorene Phenanthrene